#!/usr/bin/env python3
"""
ECG Reference Card - 40+ Abnormalities with Diagnostic Criteria
Builds a professional multi-page PDF reference card using ReportLab.
"""

from reportlab.lib.pagesizes import A4
from reportlab.lib import colors
from reportlab.lib.units import mm, cm
from reportlab.lib.styles import ParagraphStyle, getSampleStyleSheet
from reportlab.lib.enums import TA_LEFT, TA_CENTER, TA_RIGHT
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    HRFlowable, KeepTogether, PageBreak
)
from reportlab.platypus.flowables import BalancedColumns
from reportlab.lib.colors import HexColor, white, black
import os

OUTPUT = "/home/daytona/workspace/ecg-reference/ECG_Reference_Card.pdf"

# ── Colour palette ────────────────────────────────────────────────────────────
C_DARK_RED   = HexColor("#8B0000")
C_RED        = HexColor("#C0392B")
C_ORANGE     = HexColor("#E67E22")
C_AMBER      = HexColor("#F39C12")
C_BLUE_DARK  = HexColor("#1A3A5C")
C_BLUE       = HexColor("#2980B9")
C_BLUE_LIGHT = HexColor("#EBF5FB")
C_TEAL       = HexColor("#117A65")
C_TEAL_LIGHT = HexColor("#E8F8F5")
C_PURPLE     = HexColor("#6C3483")
C_PURPLE_LIGHT = HexColor("#F5EEF8")
C_GREEN      = HexColor("#1E8449")
C_GREEN_LIGHT = HexColor("#EAFAF1")
C_GREY_DARK  = HexColor("#2C3E50")
C_GREY       = HexColor("#566573")
C_GREY_LIGHT = HexColor("#F2F3F4")
C_GREY_MID   = HexColor("#BDC3C7")
C_YELLOW_LIGHT = HexColor("#FDFAE6")
C_PINK_LIGHT = HexColor("#FDEDEC")

# ── Page setup ────────────────────────────────────────────────────────────────
PAGE_W, PAGE_H = A4
MARGIN = 14 * mm
DOC_W  = PAGE_W - 2 * MARGIN

# ── Styles ────────────────────────────────────────────────────────────────────
def make_styles():
    base = getSampleStyleSheet()
    S = {}

    S['cover_title'] = ParagraphStyle(
        'cover_title', fontName='Helvetica-Bold',
        fontSize=32, textColor=white, alignment=TA_CENTER, leading=40,
        spaceAfter=6
    )
    S['cover_sub'] = ParagraphStyle(
        'cover_sub', fontName='Helvetica',
        fontSize=13, textColor=HexColor("#D6EAF8"), alignment=TA_CENTER, leading=18
    )
    S['cover_source'] = ParagraphStyle(
        'cover_source', fontName='Helvetica-Oblique',
        fontSize=9, textColor=HexColor("#AED6F1"), alignment=TA_CENTER, leading=12
    )
    S['section_head'] = ParagraphStyle(
        'section_head', fontName='Helvetica-Bold',
        fontSize=12, textColor=white, alignment=TA_LEFT, leading=15,
        leftIndent=4
    )
    S['card_title'] = ParagraphStyle(
        'card_title', fontName='Helvetica-Bold',
        fontSize=8.5, textColor=C_GREY_DARK, leading=11, spaceAfter=1
    )
    S['card_body'] = ParagraphStyle(
        'card_body', fontName='Helvetica',
        fontSize=7.5, textColor=C_GREY_DARK, leading=10.5, spaceAfter=0
    )
    S['card_crit'] = ParagraphStyle(
        'card_crit', fontName='Helvetica-Bold',
        fontSize=7.5, textColor=C_BLUE_DARK, leading=10.5
    )
    S['card_key'] = ParagraphStyle(
        'card_key', fontName='Helvetica-BoldOblique',
        fontSize=7.2, textColor=C_RED, leading=10
    )
    S['tag'] = ParagraphStyle(
        'tag', fontName='Helvetica-Bold',
        fontSize=6.5, textColor=white, leading=9, alignment=TA_CENTER
    )
    S['footer'] = ParagraphStyle(
        'footer', fontName='Helvetica',
        fontSize=7, textColor=C_GREY, alignment=TA_CENTER, leading=9
    )
    S['toc_head'] = ParagraphStyle(
        'toc_head', fontName='Helvetica-Bold',
        fontSize=10, textColor=C_BLUE_DARK, leading=13, spaceAfter=2
    )
    S['toc_item'] = ParagraphStyle(
        'toc_item', fontName='Helvetica',
        fontSize=8.5, textColor=C_GREY_DARK, leading=12, leftIndent=8
    )
    S['normal_head'] = ParagraphStyle(
        'normal_head', fontName='Helvetica-Bold',
        fontSize=9, textColor=C_BLUE_DARK, leading=12, spaceAfter=2, spaceBefore=4
    )
    S['normal_body'] = ParagraphStyle(
        'normal_body', fontName='Helvetica',
        fontSize=8, textColor=C_GREY_DARK, leading=11, spaceAfter=1
    )
    S['table_head'] = ParagraphStyle(
        'table_head', fontName='Helvetica-Bold',
        fontSize=7.5, textColor=white, leading=10, alignment=TA_CENTER
    )
    S['table_cell'] = ParagraphStyle(
        'table_cell', fontName='Helvetica',
        fontSize=7, textColor=C_GREY_DARK, leading=9.5
    )
    S['table_cell_bold'] = ParagraphStyle(
        'table_cell_bold', fontName='Helvetica-Bold',
        fontSize=7, textColor=C_GREY_DARK, leading=9.5
    )
    return S

S = make_styles()

# ── Helper: coloured section banner ──────────────────────────────────────────
def section_banner(title, color=C_BLUE_DARK, icon=""):
    label = f"{icon}  {title}" if icon else title
    t = Table([[Paragraph(label, S['section_head'])]],
              colWidths=[DOC_W])
    t.setStyle(TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), color),
        ('ROWBACKGROUNDS', (0, 0), (-1, -1), [color]),
        ('TOPPADDING', (0, 0), (-1, -1), 5),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 5),
        ('LEFTPADDING', (0, 0), (-1, -1), 8),
        ('RIGHTPADDING', (0, 0), (-1, -1), 8),
        ('ROUNDEDCORNERS', [3, 3, 3, 3]),
    ]))
    return t

# ── Helper: single condition card ────────────────────────────────────────────
def condition_card(num, name, criteria_lines, key_pearl, bg=C_BLUE_LIGHT, tag_color=C_BLUE):
    """Returns a Table that looks like a card."""
    num_cell = Paragraph(f"<b>{num}</b>", ParagraphStyle(
        'num', fontName='Helvetica-Bold', fontSize=10,
        textColor=tag_color, alignment=TA_CENTER, leading=13
    ))
    title_cell = Paragraph(f"<b>{name}</b>", S['card_title'])
    criteria_text = "<br/>".join(
        f"<bullet>&bull;</bullet> {line}" for line in criteria_lines
    )
    crit_cell = Paragraph(criteria_text, S['card_body'])
    pearl_cell = Paragraph(f"<i>&#9733; {key_pearl}</i>", S['card_key'])

    inner = Table(
        [[title_cell], [crit_cell], [pearl_cell]],
        colWidths=[DOC_W * 0.87]
    )
    inner.setStyle(TableStyle([
        ('TOPPADDING', (0, 0), (-1, -1), 1),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 1),
        ('LEFTPADDING', (0, 0), (-1, -1), 0),
        ('RIGHTPADDING', (0, 0), (-1, -1), 0),
    ]))

    outer = Table(
        [[num_cell, inner]],
        colWidths=[DOC_W * 0.07, DOC_W * 0.93]
    )
    outer.setStyle(TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), bg),
        ('TOPPADDING', (0, 0), (-1, -1), 5),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 5),
        ('LEFTPADDING', (0, 0), (0, 0), 4),
        ('LEFTPADDING', (1, 0), (1, 0), 4),
        ('RIGHTPADDING', (0, 0), (-1, -1), 6),
        ('VALIGN', (0, 0), (-1, -1), 'TOP'),
        ('BOX', (0, 0), (-1, -1), 0.5, C_GREY_MID),
        ('LINEBELOW', (0, 0), (-1, -1), 0.3, C_GREY_MID),
    ]))
    return outer

# ── Helper: two-column card row ───────────────────────────────────────────────
def two_col_cards(card_a, card_b):
    gap = 3 * mm
    col_w = (DOC_W - gap) / 2
    t = Table([[card_a, card_b]], colWidths=[col_w, col_w])
    t.setStyle(TableStyle([
        ('VALIGN', (0, 0), (-1, -1), 'TOP'),
        ('LEFTPADDING', (0, 0), (-1, -1), 0),
        ('RIGHTPADDING', (0, 0), (-1, -1), 0),
        ('TOPPADDING', (0, 0), (-1, -1), 0),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 2),
        ('INNERGRID', (0, 0), (-1, -1), 0, white),
        ('COLUMNPADDING', (1, 0), (1, 0), gap / 2),
    ]))
    return t

# ── Helper: mini single-column card (for 2-wide layout) ──────────────────────
def mini_card(num, name, criteria_lines, key_pearl, bg=C_BLUE_LIGHT, tag_color=C_BLUE):
    col_w = (DOC_W - 3 * mm) / 2
    num_cell = Paragraph(f"<b>{num}</b>", ParagraphStyle(
        'num2', fontName='Helvetica-Bold', fontSize=9,
        textColor=tag_color, alignment=TA_CENTER, leading=12
    ))
    title_cell = Paragraph(f"<b>{name}</b>", S['card_title'])
    criteria_text = "<br/>".join(
        f"<bullet>&bull;</bullet> {line}" for line in criteria_lines
    )
    crit_cell = Paragraph(criteria_text, S['card_body'])
    pearl_cell = Paragraph(f"<i>&#9733; {key_pearl}</i>", S['card_key'])

    inner = Table(
        [[title_cell], [crit_cell], [pearl_cell]],
        colWidths=[col_w * 0.86]
    )
    inner.setStyle(TableStyle([
        ('TOPPADDING', (0, 0), (-1, -1), 1),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 1),
        ('LEFTPADDING', (0, 0), (-1, -1), 0),
        ('RIGHTPADDING', (0, 0), (-1, -1), 0),
    ]))
    outer = Table(
        [[num_cell, inner]],
        colWidths=[col_w * 0.09, col_w * 0.91]
    )
    outer.setStyle(TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), bg),
        ('TOPPADDING', (0, 0), (-1, -1), 5),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 5),
        ('LEFTPADDING', (0, 0), (0, 0), 3),
        ('LEFTPADDING', (1, 0), (1, 0), 3),
        ('RIGHTPADDING', (0, 0), (-1, -1), 4),
        ('VALIGN', (0, 0), (-1, -1), 'TOP'),
        ('BOX', (0, 0), (-1, -1), 0.5, C_GREY_MID),
    ]))
    return outer

# ── Helper: comparison table ──────────────────────────────────────────────────
def comparison_table(headers, rows, col_colors=None):
    header_row = [Paragraph(h, S['table_head']) for h in headers]
    data = [header_row]
    for row in rows:
        data.append([Paragraph(str(cell), S['table_cell']) for cell in row])

    col_count = len(headers)
    col_w = DOC_W / col_count

    t = Table(data, colWidths=[col_w] * col_count, repeatRows=1)
    style_cmds = [
        ('BACKGROUND', (0, 0), (-1, 0), C_BLUE_DARK),
        ('FONTNAME', (0, 0), (-1, 0), 'Helvetica-Bold'),
        ('FONTSIZE', (0, 0), (-1, 0), 7.5),
        ('TEXTCOLOR', (0, 0), (-1, 0), white),
        ('ALIGN', (0, 0), (-1, -1), 'LEFT'),
        ('VALIGN', (0, 0), (-1, -1), 'TOP'),
        ('TOPPADDING', (0, 0), (-1, -1), 3),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 3),
        ('LEFTPADDING', (0, 0), (-1, -1), 4),
        ('RIGHTPADDING', (0, 0), (-1, -1), 4),
        ('ROWBACKGROUNDS', (0, 1), (-1, -1), [white, C_GREY_LIGHT]),
        ('GRID', (0, 0), (-1, -1), 0.3, C_GREY_MID),
        ('FONTSIZE', (0, 1), (-1, -1), 7),
    ]
    if col_colors:
        for col_idx, col_color in col_colors.items():
            style_cmds.append(('BACKGROUND', (col_idx, 0), (col_idx, 0), col_color))
    t.setStyle(TableStyle(style_cmds))
    return t

# ── Page numbering callback ───────────────────────────────────────────────────
def on_page(canvas, doc):
    canvas.saveState()
    # Footer line
    canvas.setStrokeColor(C_BLUE_DARK)
    canvas.setLineWidth(0.5)
    canvas.line(MARGIN, 18 * mm, PAGE_W - MARGIN, 18 * mm)
    # Footer text
    canvas.setFont('Helvetica', 6.5)
    canvas.setFillColor(C_GREY)
    canvas.drawString(MARGIN, 13 * mm,
        "ECG Reference Card  |  Based on Harrison's 22E, Goldman-Cecil Medicine, Medical Physiology")
    canvas.drawRightString(PAGE_W - MARGIN, 13 * mm,
        f"Page {doc.page}")
    canvas.restoreState()

def on_first_page(canvas, doc):
    # Full cover background
    canvas.setFillColor(C_BLUE_DARK)
    canvas.rect(0, 0, PAGE_W, PAGE_H, fill=1, stroke=0)
    # ECG waveform decoration strip (simulated)
    canvas.setStrokeColor(HexColor("#1A5276"))
    canvas.setLineWidth(1)
    canvas.line(0, PAGE_H * 0.52, PAGE_W, PAGE_H * 0.52)

# ── All 40+ ECG conditions data ───────────────────────────────────────────────
CONDITIONS = {
    "SINUS RHYTHMS": [
        {
            "num": "01", "name": "Normal Sinus Rhythm",
            "criteria": [
                "Rate 60-100 bpm",
                "P wave before every QRS; every QRS after a P",
                "P upright in I, II, aVF; inverted in aVR",
                "PR 120-200 ms; QRS < 120 ms",
            ],
            "pearl": "The reference standard. Deviation from this = abnormal.",
            "bg": C_GREEN_LIGHT, "tag": C_GREEN
        },
        {
            "num": "02", "name": "Sinus Bradycardia",
            "criteria": [
                "Rate < 60 bpm",
                "All morphologies (P, PR, QRS) completely NORMAL",
                "Just slow",
            ],
            "pearl": "Athletes, beta-blockers, hypothyroidism, inferior MI, sick sinus.",
            "bg": C_BLUE_LIGHT, "tag": C_BLUE
        },
        {
            "num": "03", "name": "Sinus Tachycardia",
            "criteria": [
                "Rate > 100 bpm",
                "All morphologies (P, PR, QRS) completely NORMAL",
                "P wave always upright in II",
            ],
            "pearl": "Always find the CAUSE. It is a symptom, never a primary diagnosis.",
            "bg": C_BLUE_LIGHT, "tag": C_BLUE
        },
        {
            "num": "04", "name": "Sinus Arrhythmia",
            "criteria": [
                "Rate varies with respiration (increases inspiration, decreases expiration)",
                "R-R variation > 10% between fastest and slowest",
                "All P wave morphologies and PR intervals identical",
            ],
            "pearl": "Normal finding; common in young patients and athletes.",
            "bg": C_BLUE_LIGHT, "tag": C_BLUE
        },
    ],
    "ATRIAL ABNORMALITIES": [
        {
            "num": "05", "name": "Right Atrial Overload (P-pulmonale)",
            "criteria": [
                "P wave amplitude >= 2.5 mm in II, III, aVF (tall peaked P)",
                "P wave duration NORMAL (< 120 ms)",
                "Large initial positive component of P in V1",
            ],
            "pearl": "COPD, pulmonary HTN, PE, tricuspid stenosis.",
            "bg": C_TEAL_LIGHT, "tag": C_TEAL
        },
        {
            "num": "06", "name": "Left Atrial Abnormality (P-mitrale)",
            "criteria": [
                "P wave duration >= 120 ms with notched 'M-shape' in II",
                "Biphasic P in V1: prominent DEEP negative terminal component (> 1 mm deep AND > 1 mm wide)",
                "P wave amplitude usually normal",
            ],
            "pearl": "Mitral stenosis, LV failure, hypertension, aortic stenosis.",
            "bg": C_TEAL_LIGHT, "tag": C_TEAL
        },
    ],
    "CHAMBER HYPERTROPHY": [
        {
            "num": "07", "name": "Left Ventricular Hypertrophy (LVH)",
            "criteria": [
                "Sokolow-Lyon: S(V1) + R(V5 or V6) > 35 mm",
                "Cornell: R(aVL) + S(V3) > 28 mm (M) or > 20 mm (F)",
                "R in aVL alone > 11 mm",
                "LV strain: ST depression + asymmetric T inversion in I, aVL, V5-V6",
                "Often: LAD, left atrial abnormality",
            ],
            "pearl": "Sensitivity only 30-50%. Specificity 85-95%. Echocardiography is definitive.",
            "bg": C_PURPLE_LIGHT, "tag": C_PURPLE
        },
        {
            "num": "08", "name": "Right Ventricular Hypertrophy (RVH)",
            "criteria": [
                "R >= S wave in V1 (tall R in V1) - HALLMARK",
                "Right axis deviation (QRS axis > +90 degrees)",
                "ST depression + T-wave inversion V1-V3 (RV strain)",
                "Deep S waves in I, V5, V6",
                "Right atrial overload often accompanies",
            ],
            "pearl": "Pulmonary HTN, pulmonary stenosis, COPD, ASD, Tetralogy of Fallot.",
            "bg": C_PURPLE_LIGHT, "tag": C_PURPLE
        },
    ],
    "AV CONDUCTION BLOCKS": [
        {
            "num": "09", "name": "1st Degree AV Block",
            "criteria": [
                "PR interval > 200 ms (> 5 small boxes)",
                "Every P wave is followed by a QRS - NOTHING DROPPED",
                "PR interval prolonged but CONSTANT",
                "QRS usually narrow and normal",
            ],
            "pearl": "Usually benign. Digoxin, beta-blockers, inferior MI, high vagal tone.",
            "bg": C_YELLOW_LIGHT, "tag": C_AMBER
        },
        {
            "num": "10", "name": "2nd Degree AV Block - Mobitz I (Wenckebach)",
            "criteria": [
                "PR interval progressively LENGTHENS with each beat",
                "Until one P wave is not conducted (QRS dropped)",
                "After dropped beat, PR resets to shortest, cycle repeats",
                "RR intervals progressively SHORTEN before pause",
                "GROUPED BEATING pattern - characteristic",
            ],
            "pearl": "Benign; AV nodal level. Inferior MI (RCA). Usually no pacemaker.",
            "bg": C_YELLOW_LIGHT, "tag": C_AMBER
        },
        {
            "num": "11", "name": "2nd Degree AV Block - Mobitz II",
            "criteria": [
                "PR interval is CONSTANT (does NOT prolong)",
                "Sudden unexpected non-conducted P wave (QRS dropped without warning)",
                "Often associated with WIDE QRS complex",
                "May be 2:1, 3:1 pattern",
            ],
            "pearl": "DANGEROUS - infranodal. High risk progression to complete block. Pacemaker needed.",
            "bg": C_PINK_LIGHT, "tag": C_RED
        },
        {
            "num": "12", "name": "3rd Degree (Complete) AV Block",
            "criteria": [
                "COMPLETE AV dissociation - P and QRS are INDEPENDENT",
                "P wave rate > QRS rate (P marches faster)",
                "Narrow QRS escape (junctional, 40-60 bpm) = proximal block",
                "Wide QRS escape (ventricular, 20-40 bpm) = distal block",
                "No fixed PR relationship anywhere on strip",
            ],
            "pearl": "EMERGENCY. Stokes-Adams attack (syncope). Urgent temporary pacemaker.",
            "bg": C_PINK_LIGHT, "tag": C_DARK_RED
        },
    ],
    "BUNDLE BRANCH BLOCKS": [
        {
            "num": "13", "name": "Right Bundle Branch Block (RBBB)",
            "criteria": [
                "QRS >= 120 ms (wide)",
                "rSR' pattern in V1 ('rabbit ears' / M-shape) - HALLMARK",
                "Wide slurred S wave in I, aVL, V5, V6",
                "T-wave inversion in V1-V2 (secondary change - NORMAL)",
            ],
            "pearl": "T-wave inversion in V1-V2 is NORMAL in RBBB - not ischemia. New RBBB = consider PE.",
            "bg": C_BLUE_LIGHT, "tag": C_BLUE
        },
        {
            "num": "14", "name": "Left Bundle Branch Block (LBBB)",
            "criteria": [
                "QRS >= 120 ms (wide)",
                "Broad, monophasic R in I, aVL, V5-V6 (no septal q waves!)",
                "rS or QS pattern in V1 (deep broad S or entirely negative)",
                "T-wave inversion in I, aVL, V5-V6 (secondary - NORMAL)",
                "Left axis deviation common",
            ],
            "pearl": "New LBBB + chest pain = STEMI equivalent. No septal Q waves is the key clue.",
            "bg": C_BLUE_LIGHT, "tag": C_BLUE_DARK
        },
        {
            "num": "15", "name": "Left Anterior Fascicular Block (LAFB)",
            "criteria": [
                "Left axis deviation (axis more negative than -45 degrees)",
                "qR pattern in leads I and aVL",
                "rS pattern in leads II, III, aVF",
                "QRS slightly prolonged but < 120 ms",
            ],
            "pearl": "Most common cause of marked LAD in adults.",
            "bg": C_BLUE_LIGHT, "tag": C_BLUE
        },
        {
            "num": "16", "name": "Left Posterior Fascicular Block (LPFB)",
            "criteria": [
                "Right axis deviation (axis > +110 degrees)",
                "rS pattern in I and aVL; qR in II, III, aVF",
                "QRS < 120 ms",
                "Diagnosis of EXCLUSION (rule out RVH, PE, lateral MI first)",
            ],
            "pearl": "Very rare as isolated finding. Dual blood supply makes it resistant to ischemia.",
            "bg": C_BLUE_LIGHT, "tag": C_BLUE
        },
    ],
    "ISCHEMIA AND INFARCTION": [
        {
            "num": "17", "name": "Hyperacute T Waves (Earliest STEMI)",
            "criteria": [
                "Tall, broad-based, symmetric peaked T waves in ischemic territory",
                "T wave taller than R wave in same lead",
                "Occur within MINUTES of coronary occlusion",
                "Regional distribution (not diffuse)",
            ],
            "pearl": "Earliest ECG sign of STEMI. Can revert to normal if reperfusion is rapid.",
            "bg": C_PINK_LIGHT, "tag": C_RED
        },
        {
            "num": "18", "name": "STEMI - Anterior (LAD)",
            "criteria": [
                "ST elevation (convex/tombstone) in V1-V4 (+/- I, aVL)",
                "Reciprocal ST depression in II, III, aVF",
                "Evolves: hyperacute T -> ST elevation -> T inversion -> Q waves",
                "Pathological Q waves in V1-V4 (width >= 40 ms OR depth >= 25% R)",
            ],
            "pearl": "Proximal LAD occlusion = V1-V6 + I + aVL elevation (widowmaker).",
            "bg": C_PINK_LIGHT, "tag": C_DARK_RED
        },
        {
            "num": "19", "name": "STEMI - Inferior (RCA/LCx)",
            "criteria": [
                "ST elevation in II, III, aVF",
                "Reciprocal ST depression in I, aVL (often prominent)",
                "III elevation > II elevation suggests RCA",
                "Always check right-sided leads (V3R/V4R) for RV infarct",
            ],
            "pearl": "Do right-sided leads in ALL inferior MI. RV infarct changes management entirely.",
            "bg": C_PINK_LIGHT, "tag": C_DARK_RED
        },
        {
            "num": "20", "name": "STEMI - Lateral (LCx)",
            "criteria": [
                "ST elevation in I, aVL, V5, V6",
                "Reciprocal ST depression in V1-V3 (and sometimes II, III, aVF)",
            ],
            "pearl": "High lateral MI (I, aVL only) can have very subtle, easily missed changes.",
            "bg": C_PINK_LIGHT, "tag": C_RED
        },
        {
            "num": "21", "name": "STEMI - Posterior",
            "criteria": [
                "NO direct ST elevation in standard leads",
                "Tall R wave in V1-V2 (posterior Q wave mirror image)",
                "ST depression in V1-V3 (posterior ST elevation, mirror image)",
                "Confirm with posterior leads V7-V9 (ST elevation >= 0.5 mm)",
            ],
            "pearl": "The 'hidden STEMI'. Always flip V1-V3 upside down to visualise posterior MI.",
            "bg": C_PINK_LIGHT, "tag": C_RED
        },
        {
            "num": "22", "name": "Right Ventricular Infarction",
            "criteria": [
                "In context of inferior STEMI (proximal RCA)",
                "ST elevation >= 1 mm in V3R and/or V4R",
                "Clinical: hypotension + JVD + clear lungs (Bezold-Jarisch triad)",
                "Contra-indicated: Nitrates (preload-dependent ventricle)",
            ],
            "pearl": "Fluids, NOT nitrates. Give IV fluids to maintain RV preload.",
            "bg": C_PINK_LIGHT, "tag": C_RED
        },
        {
            "num": "23", "name": "NSTEMI / Unstable Angina",
            "criteria": [
                "ST depression (horizontal or downsloping >= 1 mm) in >= 2 contiguous leads",
                "T-wave inversions in ischemic territory",
                "Troponin elevated (NSTEMI) or normal (unstable angina)",
                "No ST elevation, no Q waves",
            ],
            "pearl": "Up to 40% of NSTEMIs have a NORMAL ECG. Troponin is essential.",
            "bg": C_PINK_LIGHT, "tag": C_ORANGE
        },
        {
            "num": "24", "name": "Wellens Syndrome (LAD Warning)",
            "criteria": [
                "Biphasic T waves (Type A) or deep symmetric T inversions (Type B) in V2-V3",
                "Little or no chest pain at time of ECG",
                "No significant ST elevation; no Q waves",
                "Normal or slightly elevated troponin",
            ],
            "pearl": "Critical proximal LAD stenosis. High risk of anterior STEMI. URGENT cath.",
            "bg": C_PINK_LIGHT, "tag": C_ORANGE
        },
        {
            "num": "25", "name": "De Winter T Waves (LAD Occlusion Equivalent)",
            "criteria": [
                "Upsloping ST depression >= 1-3 mm at J-point in V1-V6",
                "Followed by tall, peaked, symmetric positive T waves",
                "ST elevation in aVR (1-2 mm)",
                "No classic ST elevation - but represents STEMI equivalent",
            ],
            "pearl": "Seen in ~2% of LAD occlusions. Treat as anterior STEMI. Activate cath lab.",
            "bg": C_PINK_LIGHT, "tag": C_ORANGE
        },
    ],
    "ATRIAL ARRHYTHMIAS": [
        {
            "num": "26", "name": "Atrial Premature Contractions (APCs)",
            "criteria": [
                "Early (premature) P wave with DIFFERENT morphology from sinus P",
                "Followed by normal QRS (usually narrow)",
                "Incomplete compensatory pause (sinus is reset)",
            ],
            "pearl": "Benign. Triggered by caffeine, alcohol, stress, electrolyte imbalance.",
            "bg": C_TEAL_LIGHT, "tag": C_TEAL
        },
        {
            "num": "27", "name": "Atrial Flutter",
            "criteria": [
                "Sawtooth flutter waves (F waves) at 250-350 bpm (classically 300 bpm)",
                "Best seen in II, III, aVF (negative sawtooth) and V1",
                "Regular or regularly irregular ventricular rate (2:1, 3:1, 4:1)",
                "Classic 2:1 flutter: ventricular rate exactly 150 bpm",
            ],
            "pearl": "Any narrow tachycardia at EXACTLY 150 bpm = flutter until proven otherwise.",
            "bg": C_TEAL_LIGHT, "tag": C_TEAL
        },
        {
            "num": "28", "name": "Atrial Fibrillation (AF)",
            "criteria": [
                "No distinct P waves - chaotic fibrillatory baseline (fine or coarse)",
                "IRREGULARLY IRREGULAR RR intervals - absolute hallmark",
                "Narrow QRS (usually) unless aberrant conduction",
                "Ventricular rate 100-170 bpm if uncontrolled",
            ],
            "pearl": "The only 'truly irregular' rhythm. If RR is irregular + wide QRS = AF with BBB or WPW.",
            "bg": C_TEAL_LIGHT, "tag": C_TEAL
        },
    ],
    "VENTRICULAR ARRHYTHMIAS": [
        {
            "num": "29", "name": "Premature Ventricular Contractions (PVCs)",
            "criteria": [
                "Wide QRS >= 120 ms with bizarre morphology",
                "No preceding P wave",
                "T wave DISCORDANT (opposite) to QRS main deflection",
                "Full compensatory pause (P-P marches through undisturbed)",
            ],
            "pearl": "Bigeminy = every other beat PVC; trigeminy = every third. Unifocal vs multifocal.",
            "bg": C_PINK_LIGHT, "tag": C_RED
        },
        {
            "num": "30", "name": "Ventricular Tachycardia (VT)",
            "criteria": [
                "Wide QRS >= 120 ms tachycardia, rate > 100 bpm (usually 140-220 bpm)",
                "AV dissociation (P waves march independently, SLOWER than QRS) - pathognomonic",
                "Fusion beats (hybrid P+VT morphology) - confirms AV dissociation",
                "Capture beats (narrow QRS amidst wide) - confirms AV dissociation",
                "QRS concordance in precordial leads (all positive or all negative V1-V6)",
            ],
            "pearl": "ALWAYS assume wide-complex tachycardia = VT. NEVER give verapamil empirically.",
            "bg": C_PINK_LIGHT, "tag": C_DARK_RED
        },
        {
            "num": "31", "name": "Ventricular Fibrillation (VF)",
            "criteria": [
                "Completely chaotic, irregular, high-frequency undulations",
                "No recognisable QRS, ST, T waves",
                "Rate: indeterminate (truly chaotic)",
            ],
            "pearl": "Cardiac arrest. IMMEDIATE unsynchronised defibrillation. CPR concurrently.",
            "bg": C_PINK_LIGHT, "tag": C_DARK_RED
        },
        {
            "num": "32", "name": "Torsades de Pointes (TdP)",
            "criteria": [
                "Polymorphic VT with twisting QRS axis around isoelectric baseline",
                "QRS amplitude oscillates - 'twisting of the points'",
                "Occurs in context of PROLONGED QT interval",
                "Rate 150-250 bpm; may self-terminate or degenerate to VF",
            ],
            "pearl": "Treat with IV Magnesium FIRST, even if Mg level is normal. Correct K+ simultaneously.",
            "bg": C_PINK_LIGHT, "tag": C_DARK_RED
        },
    ],
    "SVT / ACCESSORY PATHWAYS": [
        {
            "num": "33", "name": "AVNRT (Most Common SVT)",
            "criteria": [
                "Narrow QRS tachycardia, rate 150-250 bpm",
                "P waves buried IN or immediately after QRS (retrograde P)",
                "Pseudo-S wave in inferior leads; pseudo-R' in V1",
                "Regular rhythm; abrupt onset and termination",
                "RP interval < 70 ms",
            ],
            "pearl": "Vagal manoeuvres or adenosine terminates it. Reentry within the AV node.",
            "bg": C_PURPLE_LIGHT, "tag": C_PURPLE
        },
        {
            "num": "34", "name": "WPW Syndrome (Resting ECG)",
            "criteria": [
                "Short PR < 120 ms (pre-excitation bypasses AV node)",
                "Delta wave (slurred upstroke of QRS) - direct ventricular pre-excitation",
                "Widened QRS > 120 ms (fusion: normal + accessory pathway activation)",
                "Secondary ST-T changes (discordant to delta/QRS)",
            ],
            "pearl": "WPW + AF = life-threatening (rate >300 bpm). NEVER give digoxin or verapamil.",
            "bg": C_PURPLE_LIGHT, "tag": C_PURPLE
        },
        {
            "num": "35", "name": "Orthodromic AVRT (WPW tachycardia)",
            "criteria": [
                "Narrow QRS tachycardia (down AV node, up accessory pathway)",
                "Retrograde P wave AFTER QRS (RP > 70 ms, separated from QRS)",
                "Regular rate 150-250 bpm",
                "Rate 95% of WPW tachycardias",
            ],
            "pearl": "Narrow QRS in WPW tachycardia. Adenosine often terminates it (terminates AV conduction).",
            "bg": C_PURPLE_LIGHT, "tag": C_PURPLE
        },
    ],
    "ELECTROLYTE DISTURBANCES": [
        {
            "num": "36", "name": "Hyperkalemia",
            "criteria": [
                "K+ 5.5-6.5: Tall narrow symmetric PEAKED (tented) T waves - FIRST sign",
                "K+ 6.5-7.5: PR prolongation, P wave flattening/disappearance",
                "K+ 7.0-7.5: QRS widening begins",
                "K+ 7.5-8.0: Markedly wide bizarre QRS",
                "K+ > 8.0: Sine wave pattern -> VF -> asystole",
            ],
            "pearl": "Peaked T + wide QRS + no P = emergency. IV calcium gluconate IMMEDIATELY.",
            "bg": C_YELLOW_LIGHT, "tag": C_ORANGE
        },
        {
            "num": "37", "name": "Hypokalemia",
            "criteria": [
                "Flat or inverted T waves",
                "Prominent U waves (U wave taller than T wave in V2-V3) - HALLMARK",
                "Apparent QT prolongation (actually QU prolongation)",
                "ST depression",
            ],
            "pearl": "Predisposes to Torsades de Pointes and digitalis toxicity. Replete K+ to > 4.0 mEq/L.",
            "bg": C_YELLOW_LIGHT, "tag": C_AMBER
        },
        {
            "num": "38", "name": "Hypercalcemia",
            "criteria": [
                "Shortened QT interval (abbreviated ST segment)",
                "QTc < 360 ms",
                "Osborn waves may appear in severe cases",
                "T wave shape relatively normal",
            ],
            "pearl": "Short QT = high calcium. Classic in hyperparathyroidism, malignancy.",
            "bg": C_YELLOW_LIGHT, "tag": C_AMBER
        },
        {
            "num": "39", "name": "Hypocalcemia",
            "criteria": [
                "Prolonged QT interval (specifically prolonged ST SEGMENT)",
                "T wave shape itself remains relatively normal",
                "QTc prolonged (> 450 ms men, > 460 ms women)",
            ],
            "pearl": "QT is long but T-wave shape is normal - unlike drug QT where T wave is deformed.",
            "bg": C_YELLOW_LIGHT, "tag": C_AMBER
        },
    ],
    "SPECIAL SYNDROMES": [
        {
            "num": "40", "name": "Acute Pericarditis",
            "criteria": [
                "Diffuse CONCAVE (saddle-shaped) ST elevation in ALMOST ALL leads",
                "ST depression only in aVR and V1 (+ PR elevation in aVR)",
                "PR DEPRESSION - pathognomonic sign",
                "NO reciprocal ST depression (unlike MI)",
                "NO Q waves",
            ],
            "pearl": "Saddle shape + PR depression + no reciprocal changes = pericarditis, NOT STEMI.",
            "bg": C_TEAL_LIGHT, "tag": C_TEAL
        },
        {
            "num": "41", "name": "Cardiac Tamponade",
            "criteria": [
                "Sinus tachycardia (compensatory)",
                "LOW QRS voltage (< 5 mm all limb leads; < 10 mm all precordial leads)",
                "ELECTRICAL ALTERNANS - beat-to-beat alternation in QRS height/axis",
                "All three together = highly specific for tamponade",
            ],
            "pearl": "Alternans is caused by the heart swinging inside the pericardial effusion.",
            "bg": C_TEAL_LIGHT, "tag": C_TEAL
        },
        {
            "num": "42", "name": "Pulmonary Embolism",
            "criteria": [
                "Sinus tachycardia - most common (nonspecific)",
                "S1Q3T3: S wave in I + Q wave in III + T inversion in III",
                "New RBBB (acute RV pressure overload)",
                "Right axis deviation; T inversions V1-V4",
                "Sinus tachycardia may be the ONLY finding",
            ],
            "pearl": "S1Q3T3 is specific but seen in only ~20%. Sinus tachycardia is the most common ECG sign.",
            "bg": C_TEAL_LIGHT, "tag": C_TEAL
        },
        {
            "num": "43", "name": "Brugada Syndrome",
            "criteria": [
                "Type 1 (diagnostic): >= 2 mm COVED (dome-shape) ST elevation in V1-V2",
                "RBBB-like pattern in V1",
                "Spontaneous or drug-provoked (flecainide challenge)",
                "Type 2: Saddle-back pattern - NOT diagnostic without provocation",
            ],
            "pearl": "SCN5A Na+ channel mutation. Causes VF during sleep/fever. ICD is treatment.",
            "bg": C_PINK_LIGHT, "tag": C_RED
        },
        {
            "num": "44", "name": "Long QT Syndrome",
            "criteria": [
                "QTc >= 450 ms (men) or >= 460 ms (women)",
                "LQT1: Broad-based wide T waves; triggered by exercise/swimming",
                "LQT2: Bifid (notched) T waves; triggered by emotion/sudden sounds",
                "LQT3: Late-onset narrow T wave; events during sleep",
            ],
            "pearl": "Risk = Torsades de Pointes -> VF -> sudden death. Avoid QT-prolonging drugs.",
            "bg": C_PINK_LIGHT, "tag": C_RED
        },
        {
            "num": "45", "name": "Hypothermia (Osborn Waves)",
            "criteria": [
                "Osborn (J) waves: positive convex hump at J-point (after QRS end)",
                "Sinus bradycardia",
                "All intervals prolonged (PR, QRS, QT)",
                "J wave size correlates with degree of hypothermia",
            ],
            "pearl": "Core temp < 35C. J wave amplitude increases as temperature drops.",
            "bg": C_BLUE_LIGHT, "tag": C_BLUE
        },
        {
            "num": "46", "name": "Subarachnoid Hemorrhage (SAH)",
            "criteria": [
                "Deep, wide, symmetric T-wave inversions in multiple leads ('giant T waves')",
                "Prolonged QT interval",
                "May mimic anterior STEMI",
                "Sinus bradycardia common",
            ],
            "pearl": "CVA T-waves. Mediated by catecholamine surge. Check for headache ('thunderclap').",
            "bg": C_BLUE_LIGHT, "tag": C_BLUE
        },
        {
            "num": "47", "name": "Digoxin Effect/Toxicity",
            "criteria": [
                "Effect: Scooped ST-T ('reverse tick' sign); shortened QT; PR prolongation",
                "Toxicity: Virtually any arrhythmia possible",
                "Classic toxic rhythms: PVCs, AV block + junctional tachycardia, AF with regularised rhythm",
                "Bidirectional VT = pathognomonic for digoxin toxicity",
            ],
            "pearl": "Digoxin EFFECT (therapeutic) is not toxicity. Toxicity requires clinical correlation.",
            "bg": C_YELLOW_LIGHT, "tag": C_AMBER
        },
        {
            "num": "48", "name": "Tricyclic Antidepressant Toxicity",
            "criteria": [
                "QRS widening >= 100 ms (severe >= 160 ms)",
                "Right axis deviation of terminal QRS forces",
                "Tall R wave in aVR (> 3 mm); R:S in aVR > 0.7",
                "QT prolongation; sinus tachycardia",
            ],
            "pearl": "QRS > 100 ms = seizure risk. QRS > 160 ms = VT risk. Na bicarb is antidote.",
            "bg": C_PINK_LIGHT, "tag": C_RED
        },
    ]
}

# ── Build document ────────────────────────────────────────────────────────────
def build_pdf():
    doc = SimpleDocTemplate(
        OUTPUT,
        pagesize=A4,
        leftMargin=MARGIN,
        rightMargin=MARGIN,
        topMargin=22 * mm,
        bottomMargin=22 * mm,
        title="ECG Reference Card - 48 Abnormalities",
        author="Orris Medical AI",
        subject="ECG Diagnostic Criteria Reference",
    )

    story = []

    # ── COVER PAGE ────────────────────────────────────────────────────────────
    story.append(Spacer(1, 30 * mm))

    cover_title_t = Table(
        [[Paragraph("ECG Reference Card", S['cover_title'])]],
        colWidths=[DOC_W]
    )
    cover_title_t.setStyle(TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), C_BLUE_DARK),
        ('TOPPADDING', (0, 0), (-1, -1), 12),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 8),
        ('LEFTPADDING', (0, 0), (-1, -1), 8),
        ('RIGHTPADDING', (0, 0), (-1, -1), 8),
    ]))
    story.append(cover_title_t)
    story.append(Spacer(1, 4 * mm))

    subtitle_t = Table(
        [[Paragraph("48 ECG Abnormalities with Diagnostic Criteria", S['cover_sub'])]],
        colWidths=[DOC_W]
    )
    subtitle_t.setStyle(TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), C_BLUE),
        ('TOPPADDING', (0, 0), (-1, -1), 8),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 8),
    ]))
    story.append(subtitle_t)
    story.append(Spacer(1, 6 * mm))

    desc_t = Table([[Paragraph(
        "MBBS-Level Quick Reference  |  From Sinus Rhythms to Complex Arrhythmias<br/>"
        "Ischemia &amp; Infarction  |  Electrolyte Disorders  |  Special Syndromes<br/>"
        "<br/>Based on: Harrison's Principles 22E  |  Goldman-Cecil Medicine  |  Medical Physiology (Boron &amp; Boulpaep)",
        S['cover_source']
    )]], colWidths=[DOC_W])
    desc_t.setStyle(TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), C_BLUE_DARK),
        ('TOPPADDING', (0, 0), (-1, -1), 10),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 10),
    ]))
    story.append(desc_t)

    story.append(Spacer(1, 20 * mm))

    # Colour legend on cover
    legend_data = [
        [
            Paragraph("<b>Sinus / Normal</b>", ParagraphStyle('lg', fontName='Helvetica-Bold', fontSize=8, textColor=white)),
            Paragraph("<b>Atrial Abnormalities</b>", ParagraphStyle('lg', fontName='Helvetica-Bold', fontSize=8, textColor=white)),
            Paragraph("<b>Hypertrophy</b>", ParagraphStyle('lg', fontName='Helvetica-Bold', fontSize=8, textColor=white)),
            Paragraph("<b>AV Blocks</b>", ParagraphStyle('lg', fontName='Helvetica-Bold', fontSize=8, textColor=white)),
        ],
        [
            Paragraph("<b>Bundle Branch</b>", ParagraphStyle('lg', fontName='Helvetica-Bold', fontSize=8, textColor=white)),
            Paragraph("<b>Ischemia / MI</b>", ParagraphStyle('lg', fontName='Helvetica-Bold', fontSize=8, textColor=white)),
            Paragraph("<b>Arrhythmias</b>", ParagraphStyle('lg', fontName='Helvetica-Bold', fontSize=8, textColor=white)),
            Paragraph("<b>Special Syndromes</b>", ParagraphStyle('lg', fontName='Helvetica-Bold', fontSize=8, textColor=white)),
        ]
    ]
    legend_t = Table(legend_data, colWidths=[DOC_W / 4] * 4)
    legend_t.setStyle(TableStyle([
        ('BACKGROUND', (0, 0), (0, 0), C_GREEN),
        ('BACKGROUND', (1, 0), (1, 0), C_TEAL),
        ('BACKGROUND', (2, 0), (2, 0), C_PURPLE),
        ('BACKGROUND', (3, 0), (3, 0), C_AMBER),
        ('BACKGROUND', (0, 1), (0, 1), C_BLUE),
        ('BACKGROUND', (1, 1), (1, 1), C_DARK_RED),
        ('BACKGROUND', (2, 1), (2, 1), C_RED),
        ('BACKGROUND', (3, 1), (3, 1), C_TEAL),
        ('ALIGN', (0, 0), (-1, -1), 'CENTER'),
        ('VALIGN', (0, 0), (-1, -1), 'MIDDLE'),
        ('TOPPADDING', (0, 0), (-1, -1), 7),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 7),
        ('INNERGRID', (0, 0), (-1, -1), 0.5, white),
        ('BOX', (0, 0), (-1, -1), 0.5, white),
    ]))
    story.append(legend_t)

    story.append(Spacer(1, 10 * mm))

    # Normal values box on cover
    nv_data = [
        [Paragraph("<b>NORMAL ECG VALUES QUICK REFERENCE</b>", ParagraphStyle(
            'nvh', fontName='Helvetica-Bold', fontSize=9, textColor=white, alignment=TA_CENTER
        ))],
        [Table([
            [
                Paragraph("<b>Heart Rate</b><br/>60-100 bpm", S['normal_body']),
                Paragraph("<b>PR Interval</b><br/>120-200 ms (3-5 small boxes)", S['normal_body']),
                Paragraph("<b>QRS Duration</b><br/>70-110 ms (&lt; 3 small boxes)", S['normal_body']),
            ],
            [
                Paragraph("<b>QTc (Bazett)</b><br/>Men: &lt;450 ms | Women: &lt;460 ms", S['normal_body']),
                Paragraph("<b>QRS Axis</b><br/>-30 to +90 degrees", S['normal_body']),
                Paragraph("<b>ECG Paper</b><br/>1 small box = 0.04 s / 0.1 mV", S['normal_body']),
            ],
        ], colWidths=[DOC_W / 3] * 3)]
    ]
    nv_outer = Table(nv_data, colWidths=[DOC_W])
    nv_outer.setStyle(TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), C_BLUE_DARK),
        ('BACKGROUND', (0, 1), (-1, 1), HexColor("#EBF5FB")),
        ('TOPPADDING', (0, 0), (-1, 0), 6),
        ('BOTTOMPADDING', (0, 0), (-1, 0), 6),
        ('TOPPADDING', (0, 1), (-1, 1), 4),
        ('BOTTOMPADDING', (0, 1), (-1, 1), 4),
        ('BOX', (0, 0), (-1, -1), 0.8, C_BLUE_DARK),
    ]))
    story.append(nv_outer)

    story.append(PageBreak())

    # ── CONDITION PAGES ───────────────────────────────────────────────────────
    section_colors = {
        "SINUS RHYTHMS": C_GREEN,
        "ATRIAL ABNORMALITIES": C_TEAL,
        "CHAMBER HYPERTROPHY": C_PURPLE,
        "AV CONDUCTION BLOCKS": C_AMBER,
        "BUNDLE BRANCH BLOCKS": C_BLUE_DARK,
        "ISCHEMIA AND INFARCTION": C_DARK_RED,
        "ATRIAL ARRHYTHMIAS": C_TEAL,
        "VENTRICULAR ARRHYTHMIAS": C_RED,
        "SVT / ACCESSORY PATHWAYS": C_PURPLE,
        "ELECTROLYTE DISTURBANCES": C_ORANGE,
        "SPECIAL SYNDROMES": C_BLUE_DARK,
    }

    section_icons = {
        "SINUS RHYTHMS": "01",
        "ATRIAL ABNORMALITIES": "02",
        "CHAMBER HYPERTROPHY": "03",
        "AV CONDUCTION BLOCKS": "04",
        "BUNDLE BRANCH BLOCKS": "05",
        "ISCHEMIA AND INFARCTION": "06",
        "ATRIAL ARRHYTHMIAS": "07",
        "VENTRICULAR ARRHYTHMIAS": "08",
        "SVT / ACCESSORY PATHWAYS": "09",
        "ELECTROLYTE DISTURBANCES": "10",
        "SPECIAL SYNDROMES": "11",
    }

    for section_name, conditions in CONDITIONS.items():
        sec_color = section_colors.get(section_name, C_BLUE_DARK)
        story.append(section_banner(
            f"SECTION {section_icons.get(section_name, '')}  |  {section_name}",
            color=sec_color
        ))
        story.append(Spacer(1, 2 * mm))

        # Render cards in two-column pairs
        cards = []
        for cond in conditions:
            card = mini_card(
                num=cond["num"],
                name=cond["name"],
                criteria_lines=cond["criteria"],
                key_pearl=cond["pearl"],
                bg=cond.get("bg", C_BLUE_LIGHT),
                tag_color=cond.get("tag", C_BLUE)
            )
            cards.append(card)

        # Pair up cards into two-column rows
        i = 0
        while i < len(cards):
            if i + 1 < len(cards):
                row_t = Table(
                    [[cards[i], Spacer(3 * mm, 1), cards[i + 1]]],
                    colWidths=[(DOC_W - 3 * mm) / 2, 3 * mm, (DOC_W - 3 * mm) / 2]
                )
                row_t.setStyle(TableStyle([
                    ('VALIGN', (0, 0), (-1, -1), 'TOP'),
                    ('LEFTPADDING', (0, 0), (-1, -1), 0),
                    ('RIGHTPADDING', (0, 0), (-1, -1), 0),
                    ('TOPPADDING', (0, 0), (-1, -1), 0),
                    ('BOTTOMPADDING', (0, 0), (-1, -1), 2),
                ]))
                story.append(row_t)
                i += 2
            else:
                # Odd card - full width
                full_card = condition_card(
                    num=conditions[i]["num"],
                    name=conditions[i]["name"],
                    criteria_lines=conditions[i]["criteria"],
                    key_pearl=conditions[i]["pearl"],
                    bg=conditions[i].get("bg", C_BLUE_LIGHT),
                    tag_color=conditions[i].get("tag", C_BLUE)
                )
                story.append(full_card)
                story.append(Spacer(1, 1.5 * mm))
                i += 1

        story.append(Spacer(1, 4 * mm))

    # ── COMPARISON TABLES PAGE ────────────────────────────────────────────────
    story.append(PageBreak())
    story.append(section_banner("CRITICAL COMPARISON TABLES", color=C_BLUE_DARK))
    story.append(Spacer(1, 3 * mm))

    # Table 1: STEMI localisation
    story.append(Paragraph("STEMI Localisation by Lead Territory", S['normal_head']))
    t1 = comparison_table(
        headers=["MI Territory", "ST Elevation in", "Reciprocal Depression", "Culprit Artery"],
        rows=[
            ["Anterior", "V1-V4", "II, III, aVF", "LAD (mid-distal)"],
            ["Septal", "V1-V2", "None typically", "LAD (septal branches)"],
            ["Anterolateral", "V1-V6, I, aVL", "II, III, aVF", "Proximal LAD"],
            ["Lateral", "I, aVL, V5-V6", "V1-V3", "LCx or Diagonal"],
            ["Inferior", "II, III, aVF", "I, aVL", "RCA (80%) or LCx (20%)"],
            ["Posterior", "Tall R + ST depression V1-V3", "None (V1-V3 shows depression)", "RCA or LCx"],
            ["Right Ventricle", "V3R, V4R elevation", "—", "Proximal RCA"],
        ]
    )
    story.append(t1)
    story.append(Spacer(1, 4 * mm))

    # Table 2: AV blocks
    story.append(Paragraph("AV Block Differentiation", S['normal_head']))
    t2 = comparison_table(
        headers=["Block Type", "PR Interval", "Dropped QRS?", "Location", "Prognosis"],
        rows=[
            ["1st Degree", "Fixed, > 200 ms", "Never", "AV node", "Benign"],
            ["2nd Degree - Mobitz I", "Progressively lengthens", "Yes (after longest PR)", "AV node", "Usually benign"],
            ["2nd Degree - Mobitz II", "Fixed, constant", "Yes (sudden, no warning)", "His/Bundle branch", "Dangerous - pace"],
            ["3rd Degree (Complete)", "No relationship (AV dissociation)", "Essentially all", "Anywhere", "Emergency - pace"],
        ]
    )
    story.append(t2)
    story.append(Spacer(1, 4 * mm))

    # Table 3: Pericarditis vs STEMI
    story.append(Paragraph("Pericarditis vs STEMI - Key Differentiators", S['normal_head']))
    t3 = comparison_table(
        headers=["Feature", "Acute Pericarditis", "STEMI"],
        rows=[
            ["ST elevation shape", "Concave/saddle-shaped (upward concave)", "Convex/tombstone (upward dome)"],
            ["Distribution", "Diffuse (almost ALL leads)", "Regional/territorial (contiguous leads)"],
            ["Reciprocal ST depression", "ABSENT (only aVR/V1 show depression)", "PRESENT in opposite territory"],
            ["PR changes", "PR DEPRESSION (pathognomonic) + PR elevation in aVR", "None"],
            ["Q waves", "Absent", "Develop (mark necrosis)"],
            ["Evolution", "4 staged over days-weeks", "Hours-to-days"],
        ]
    )
    story.append(t3)
    story.append(Spacer(1, 4 * mm))

    # Table 4: Wide-complex tachycardia
    story.append(Paragraph("Wide-Complex Tachycardia: VT vs SVT with Aberrancy", S['normal_head']))
    t4 = comparison_table(
        headers=["Feature", "Favours VT", "Favours SVT + Aberrancy"],
        rows=[
            ["AV dissociation", "YES - pathognomonic for VT", "Absent"],
            ["Fusion/capture beats", "YES - confirm VT", "Absent"],
            ["QRS concordance (V1-V6)", "All positive or all negative = VT", "Mixed polarity"],
            ["QRS morphology", "Unusual/bizarre (does not fit RBBB or LBBB)", "Typical RBBB or LBBB pattern"],
            ["History", "Structural heart disease, prior MI, cardiomyopathy", "Young patient, prior SVT episodes"],
            ["Default rule", "ALWAYS assume VT first!", "Only after VT excluded"],
        ]
    )
    story.append(t4)
    story.append(Spacer(1, 4 * mm))

    # Table 5: Electrolytes and QT
    story.append(Paragraph("Electrolyte Effects on ECG", S['normal_head']))
    t5 = comparison_table(
        headers=["Electrolyte", "QT Effect", "T Wave", "P Wave/QRS", "Key Sign"],
        rows=[
            ["Hyperkalemia (mild)", "Short/normal", "Peaked, tented, narrow, symmetric", "Normal", "Tent-shaped T"],
            ["Hyperkalemia (severe)", "QRS widens/absorbs QT", "Disappears into QRS", "P flattens, disappears; QRS widens", "Sine wave pattern"],
            ["Hypokalemia", "Prolonged (QU)", "Flat/inverted", "Normal", "Prominent U wave > T wave"],
            ["Hypercalcemia", "SHORTENED", "Normal or early takeoff", "Normal", "Short QTc < 360 ms"],
            ["Hypocalcemia", "PROLONGED (ST lengthened)", "Normal shape, just delayed onset", "Normal", "Long QTc, normal T shape"],
            ["Hypomagnesemia", "Prolonged", "Flat, may invert", "Normal", "Predisposes to TdP like hypoK+"],
        ]
    )
    story.append(t5)

    # ── LIFE-THREATENING DIAGNOSES PAGE ──────────────────────────────────────
    story.append(PageBreak())
    story.append(section_banner(
        "THE 5 IMMEDIATELY LIFE-THREATENING ECG DIAGNOSES",
        color=C_DARK_RED
    ))
    story.append(Spacer(1, 3 * mm))

    life_data = [
        [
            Paragraph("<b>#</b>", S['table_head']),
            Paragraph("<b>Diagnosis</b>", S['table_head']),
            Paragraph("<b>ECG Key Finding</b>", S['table_head']),
            Paragraph("<b>Immediate Action</b>", S['table_head']),
        ],
        ["1", "STEMI",
         "Regional convex ST elevation in contiguous leads + reciprocal changes",
         "Activate cath lab NOW. Aspirin + heparin + P2Y12 inhibitor. PCI within 90 min."],
        ["2", "Ventricular Fibrillation",
         "Chaotic irregular undulations; no recognisable QRS/P/T",
         "CPR + immediate unsynchronised DEFIBRILLATION 200J biphasic. Adrenaline 1mg IV."],
        ["3", "Ventricular Tachycardia (haemodynamically unstable)",
         "Wide QRS > 120 ms tachycardia; AV dissociation; fusion/capture beats",
         "Synchronised DC cardioversion. If pulseless: defibrillate. Amiodarone 300mg IV."],
        ["4", "Complete Heart Block",
         "AV dissociation (P rate > QRS rate); wide slow escape rhythm",
         "Atropine 0.5-1mg IV (if narrow QRS escape). Transcutaneous/transvenous pacing urgently."],
        ["5", "Severe Hyperkalemia (> 7.5 mEq/L)",
         "Wide QRS + absent P waves + sine wave pattern",
         "IV Calcium gluconate 10 mL 10% IMMEDIATELY. Insulin-dextrose. Bicarbonate. Dialysis."],
    ]

    life_t = Table(life_data,
                   colWidths=[DOC_W * 0.04, DOC_W * 0.15, DOC_W * 0.40, DOC_W * 0.41],
                   repeatRows=1)
    life_style = [
        ('BACKGROUND', (0, 0), (-1, 0), C_DARK_RED),
        ('TEXTCOLOR', (0, 0), (-1, 0), white),
        ('FONTNAME', (0, 0), (-1, 0), 'Helvetica-Bold'),
        ('FONTSIZE', (0, 0), (-1, 0), 8),
        ('FONTSIZE', (0, 1), (-1, -1), 7.5),
        ('ALIGN', (0, 0), (0, -1), 'CENTER'),
        ('VALIGN', (0, 0), (-1, -1), 'TOP'),
        ('TOPPADDING', (0, 0), (-1, -1), 5),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 5),
        ('LEFTPADDING', (0, 0), (-1, -1), 5),
        ('RIGHTPADDING', (0, 0), (-1, -1), 5),
        ('GRID', (0, 0), (-1, -1), 0.5, C_GREY_MID),
        ('BACKGROUND', (0, 1), (-1, 1), HexColor("#FDEDEC")),
        ('BACKGROUND', (0, 2), (-1, 2), HexColor("#FEF9E7")),
        ('BACKGROUND', (0, 3), (-1, 3), HexColor("#FDEDEC")),
        ('BACKGROUND', (0, 4), (-1, 4), HexColor("#FEF9E7")),
        ('BACKGROUND', (0, 5), (-1, 5), HexColor("#FDEDEC")),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTNAME', (1, 1), (1, -1), 'Helvetica-Bold'),
        ('TEXTCOLOR', (1, 1), (1, -1), C_DARK_RED),
    ]
    life_t.setStyle(TableStyle(life_style))
    story.append(life_t)

    story.append(Spacer(1, 5 * mm))
    story.append(section_banner("SYSTEMATIC ECG READING APPROACH (Harrison's 22E - 14 Parameters)", color=C_BLUE_DARK))
    story.append(Spacer(1, 3 * mm))

    steps = [
        ("1", "Calibration & Technical Quality", "Confirm 25 mm/sec speed, 10 mm/mV gain. Check lead placement. Look for artefacts."),
        ("2", "Rhythm", "Regular or irregular? Any pattern to irregularity? Identify all wave types."),
        ("3", "Heart Rate", "300 / large boxes between RRs (regular). Or count QRS in 10 sec x 6 (irregular)."),
        ("4", "PR Interval / AV Conduction", "120-200 ms. Fixed? Lengthening? Every P followed by QRS?"),
        ("5", "QRS Duration", "< 120 ms = narrow. >= 120 ms = wide (BBB, VT, paced, hyperK+, toxic)."),
        ("6", "QT / QTc", "QTc = QT / sqrt(RR in seconds). Men < 450 ms; Women < 460 ms."),
        ("7", "Mean QRS Axis", "Check leads I and aVF: +/+ = normal; +/- = LAD; -/+ = RAD; -/- = extreme."),
        ("8", "P Wave Morphology", "Upright I, II, aVF. Peaked? Broad/notched? Biphasic V1?"),
        ("9", "QRS Voltages", "LVH criteria? Low voltage (< 5 mm limb, < 10 mm precordial)?"),
        ("10", "R-Wave Progression", "R grows from V1 to V5. Transition at V3-V4. Absent = anterior pathology."),
        ("11", "Abnormal Q Waves", "Width >= 40 ms OR depth >= 25% R wave height = pathological."),
        ("12", "ST Segments", "Elevation? Depression? Shape? Regional or diffuse? Measure at J-point."),
        ("13", "T Waves", "Inverted (ischaemia, strain, BBB)? Peaked (hyperK+)? Bifid (LQT2)?"),
        ("14", "U Waves", "Prominent U > T wave = hypoK+. Inverted U wave = ischaemia."),
    ]

    step_data = [[
        Paragraph(f"<b>{s}</b>", ParagraphStyle('sn', fontName='Helvetica-Bold', fontSize=8, textColor=white, alignment=TA_CENTER)),
        Paragraph(f"<b>{n}</b>", ParagraphStyle('sc', fontName='Helvetica-Bold', fontSize=7.5, textColor=C_BLUE_DARK)),
        Paragraph(desc, S['table_cell'])
    ] for s, n, desc in steps]

    # Add header
    step_data.insert(0, [
        Paragraph("<b>#</b>", S['table_head']),
        Paragraph("<b>Parameter</b>", S['table_head']),
        Paragraph("<b>What to Look For</b>", S['table_head']),
    ])

    step_t = Table(step_data,
                   colWidths=[DOC_W * 0.05, DOC_W * 0.25, DOC_W * 0.70],
                   repeatRows=1)
    step_t.setStyle(TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), C_BLUE_DARK),
        ('TEXTCOLOR', (0, 0), (-1, 0), white),
        ('FONTNAME', (0, 0), (-1, 0), 'Helvetica-Bold'),
        ('FONTSIZE', (0, 0), (-1, 0), 8),
        ('FONTSIZE', (0, 1), (-1, -1), 7.5),
        ('BACKGROUND', (0, 1), (0, -1), C_BLUE),
        ('TEXTCOLOR', (0, 1), (0, -1), white),
        ('ALIGN', (0, 0), (0, -1), 'CENTER'),
        ('VALIGN', (0, 0), (-1, -1), 'MIDDLE'),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 4),
        ('RIGHTPADDING', (0, 0), (-1, -1), 4),
        ('ROWBACKGROUNDS', (1, 1), (-1, -1), [white, C_GREY_LIGHT]),
        ('GRID', (0, 0), (-1, -1), 0.3, C_GREY_MID),
    ]))
    story.append(step_t)

    # ── BUILD ─────────────────────────────────────────────────────────────────
    doc.build(story, onFirstPage=on_page, onLaterPages=on_page)
    print(f"PDF saved to: {OUTPUT}")
    return OUTPUT


if __name__ == "__main__":
    build_pdf()

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/ecg-reference/build_ecg_reference.py'

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/ecg-reference/build_ecg_reference.py'